Ford Engine AC Problem

[whitewinghunter]

Sounds to me like your Recirulation door is not working properly. Make sure it's on and opening and closing off correctly. You would be surprised at what a park pamphlet stuck across the reciculation door could do. Just my 0.02


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[weatherguru1]

As to what was suggested by the previous post, Evans Tempcon rep confirmed the following: Evacuated the system, pull new vacuum, replace freon with NEW ONLY. I don't understand how Freon OLD is Different from Freon NEW but I'm more than willing to learn. Your turn guys.

[JMorton]

I'm having the same problem with my 2018 Georgetown XL 369 DS
Ford Dealer diagnosed there is a problem with the directional damper in the heat/cool mixing box.
The heat works great but when turned cooling if the damper doesn't direct all the air through the cooling coil you're left with a lack of cooling.

[ScottBrownstein]

Originally Posted by weatherguru1

As to what was suggested by the previous post, Evans Tempcon rep confirmed the following: Evacuated the system, pull new vacuum, replace freon with NEW ONLY. I don't understand how Freon OLD is Different from Freon NEW but I'm more than willing to learn. Your turn guys.

First off, they probably said, recover existing refrigerant, then pull a vacuum and then replace with the correct weight of fresh refrigerant, probably 134a. Now there isn't much refrigerant in that system and the only way to put refrigerant in an automobile system and know that it is the correct amount is to charge by weight.


Trust me, the cost of the 134a is the cheapest part of that process. They also may be worried about water vapor contamination, the pump down will get rid of that as well.

BTW, I would bet that the target evaporator temperature is around 45 degrees F. You will never see 38 degree air, and if it is hot in the coach, you will be lucky to see 55 degree air. As the temp in the coach falls, so will the duct air temperature.

[2Evil4U]

Totally random aside. On the expedition I bought from Copart to fix for my daughter, there is a vacuum operated valve in the heater hose to the heater core. It is teed into the vacuum hose that operates the recirc flapper door. If that gets disconnected by let's say someone changing the battery in a hurry, the system will act all sorts of funny.

[Wolverine 1945]

Home A/C is doing a good job if you are getting a 20 degree drop !!!

[weatherguru1]

I don't know where to start. My wife and I went to the FROG Rally in Elkhart Indiana the past week. Just returned home in 86 degree temperatures through Ohio. AC didnot keep us cool. I had this 2015 Georgetown unit to the Forest River factory on Wednesday 8-15-18. The Tech, AC Licensed, brought out a very nice, expensive machine to check the AC. He explained to me the process and proceeded to hook it up, program it to my units specks and left it do its job. It evacuated the 134a, drained the oil, fully vacuumed the system, and refilled it to 2.75 psi of 134a. This is the number given to them for an Evens Tempcon unit on a Ford53 chaise which Forest River uses.

He told me to never expect better than a 20 to 22 degree drop over ambient air temperature. After a 15 minute trial run at 77 degrees, and a 2 degree rise in air temp over that time, I basically came away a 2 degree loss from when I arrived there. At 86 degrees on Saturday the 18th, on the four lanes, my digital readout varied between 60 and 64 degrees. He apparently is right-on with his statement.

I consider this to be extremely poor performance. Can some one please tell me who to contact to have this unit fixed. F350s I know do much better.

[ScottBrownstein]

Originally Posted by weatherguru1

I consider this to be extremely poor performance. Can some one please tell me who to contact to have this unit fixed. F350s I know do much better.

OK, he is right about the 20 degrees, but it is not over outdoor ambient, it is over the temperature of air going into the evaporator. On most units that means you will get better performance if you do not draw air in from outside but recirculate indoor air. On my car this is simple as it shows a little closed loop arrow over the button.

Must admit that on my 2014 F-53 chassis, I have never figured out the air controls that well. It should be MAX/AC for recirculate or AC for draw in outside air, but I would check.

Sounds like your problem is elsewhere (air baffle, hot water valve, etc) The tech just check the AC units functions and unless the thermostat or compressor clutch is bad...not an AC unit issue.

My coach doesn't cool all that well and I have run the generator and rooftop underway and I know a lot of others do as well.

[Wolverine 1945]

Originally Posted by weatherguru1

I don't know where to start. My wife and I went to the FROG Rally in Elkhart Indiana the past week. Just returned home in 86 degree temperatures through Ohio. AC didnot keep us cool. I had this 2015 Georgetown unit to the Forest River factory on Wednesday 8-15-18. The Tech, AC Licensed, brought out a very nice, expensive machine to check the AC. He explained to me the process and proceeded to hook it up, program it to my units specks and left it do its job. It evacuated the 134a, drained the oil, fully vacuumed the system, and refilled it to 2.75 psi of 134a. This is the number given to them for an Evens Tempcon unit on a Ford53 chaise which Forest River uses.

He told me to never expect better than a 20 to 22 degree drop over ambient air temperature. After a 15 minute trial run at 77 degrees, and a 2 degree rise in air temp over that time, I basically came away a 2 degree loss from when I arrived there. At 86 degrees on Saturday the 18th, on the four lanes, my digital readout varied between 60 and 64 degrees. He apparently is right-on with his statement.

I consider this to be extremely poor performance. Can some one please tell me who to contact to have this unit fixed. F350s I know do much better.

FORD !!!

[FORKLIFMAN]

Originally Posted by ScottBrownstein

OK, he is right about the 20 degrees, but it is not over outdoor ambient, it is over the temperature of air going into the evaporator. On most units that means you will get better performance if you do not draw air in from outside but recirculate indoor air. On my car this is simple as it shows a little closed loop arrow over the button.

Must admit that on my 2014 F-53 chassis, I have never figured out the air controls that well. It should be MAX/AC for recirculate or AC for draw in outside air, but I would check.

Sounds like your problem is elsewhere (air baffle, hot water valve, etc) The tech just check the AC units functions and unless the thermostat or compressor clutch is bad...not an AC unit issue.

My coach doesn't cool all that well and I have run the generator and rooftop underway and I know a lot of others do as well.

X2.

If your trying to cool your entire MH it will not happen. The dash air is only designed to cool a car or cab of a truck. On SUVs there is a rear evaporator to help cool down the vehicles. My F550 does great when it's not too hot! ON hot days, I need to run the generator and the roof a/c, and maybe both a/c units on extremely hot days.

All that said, on top of it,,,, it's a FORD!

[weatherguru1]

Guys, Just to clear things up. I have an insulated curtain, behind the two seats, clear to the floor. Never would I expect to cool the entire unit from the dash AC. All other components have been checked and found to be functional.

The Evens Temp Con Rep told me to change the setting to regular AC every ten minutes or so, for about 1 minute, to put new air in the unit. I know this is self defeating but thats what was relayed. I have no problems following directions, just ask my wife. Phone calls to be made for sure.

Thanks for following my frustration.

[Fkrel]

What speed are you running your blower fan at? the lower the fan speed the colder the output temp should be, check and see if the recirulate door is closing and you are not pulling any air in from the outside. If you have a hot water valve check it if it is hot both sides its on or bad if its warm its on or bad you can use a small pair of needle nose vise grips and pinch the hose to the valve and then check the cooling temp if it gets colder the valve is leaking past. another thing on some units they have a freeze switch to keep the evaporator from getting to cold and iceing up it kicks the compressor off until it warms up and then kicks back on these have caused lots of problems. Make sure the engine fan is pulling air thru the condenser or if you have a electric fan make sure its working. When I do air conditioning the temp should get cold enough to cycle the compressior with the windows closed at 1000 rpm and the fan on the lowest setting after running about 10 to 15 min. and output temp should be atleast 55 degrees and I like it when they get to 46 degrees. While its running watch the compressior and make a note of the temp when it kicks out and also when it kicks back in watch the center of the pulley with a flashlight you will see it kick out and in also what is the model number of the unit installed in your rv I would like to see if it is equiped with a freeze switch

[aircommuter]

I’m not sure about your vehicle but some have variable displacement compressors. Those require a pulse width modulation signal which depends on various sensors in the system. You can identify those units by looking at the compressor and see where the feed wire goes, if it connects to the back of the compressor then it is variable.

[weatherguru1]

Aircommuter has just throne me a curve ball. What is a variable displacement compressors? Can't say I ever heard that term before. Can you explain it better? What varies on the compressor? How does displacement change and why?
Did Ford use them on a F53? Are they a bad thing in AC circles? If so what should I look for specifically with regard to the wiring? I am very lost here.

[aircommuter]

Most automotive A/C compressors today are axial piston compressors. There is a swash plate that sits at a fixed angle (constant displacement) or the angle can be varied all the way to 90 degrees to the pistons which is zero displacement.
They are an offshoot of hydraulic pumps used in hydrostatic drive systems.
In automotive A/C systems they eliminate the on off surge that is felt when the clutch activates, the variables don’t use a clutch as they come on by varying the swash plate. It also works seamlessly with climate control systems just giveing amount of displacement needed for the moment. The pictures are a fixed displacement version. I didn’t have a variable apart in the shop, I do have a new variable I could send if needed.

[weatherguru1]

Thanks aircommuter for the picture and information. I never saw the inside of an AC unit. Never to old to learn. As a side note then, am I barking up the wrong tree when I say my unit should get colder? At 93 degrees I get 70 degree output.

[weatherguru1]

Fkrel, I did not have time to gather any of that info yet. I hope to get it this week. As I said before everything was gone over by Ford Employees over the last year and a half.

[aircommuter]

That outlet temperature is totally unacceptable. When ambient temperature rises so should refrigerant pressure, unless the compressor is not able to perform. The outlet temperature should easily be in the mid 50’s. I don’t know if those motor homes like yours use a variable or a fixed displacement compressor. Either way applying constant current to the compressor for testing purposes is ok and would be one step in the diagnosis. A/C systems are pretty straight forward and all tests could be done in a couple hours. If you have a variable displacement and applying test voltage solves the problem then one must go through a diagnostic tree to find out why the computer is not supplying voltage. First things first, one step at a time should reveal the problem.

[Retired JSO]

A small vacuum leak or faulty spring will cause the mixing door to stay partly ajar causing some air to flow through the heater core thus increasing outlet temperature.

[aircommuter]

While I am not directly familiar with this vehicle. I do know that most vehicles today do not use vacuum to operate heater/defroster doors. Many makes and models have door problems in their systems. The scenario is the doors are controlled by stepper motors, the vehicle computer cycles the motors every 20 starts so it can verify the full open and full closed positions in relationship to the requested position of the doors. They have stops on the motor shafts, they are plastic, they break, then the door becomes the stop then they break. So if the driver makes a lot of stop start sequences those doors break sooner.
In any case simple tests can be easily performed to see if that is the case.